Exhaust system for a load dumping vehicle

ABSTRACT

A load dumping vehicle including a frame, a gas turbine engine supported by the frame and a dump body pivotally connected to the frame for movement relative to the frame between a load carrying position and a dump position. Exhaust from the engine is ducted under the dump body through first and second exhaust ducts. Part of the exhaust flows into the dump body to heat the load. The ducts are connected at adjacent ends by a coupling structure which seals the juncture of the exhaust ducts when the dump body is in its load carrying and in its dump positions.

United States Patent Vincenty 51 Oct. 3, 1972 [72] Inventor: Henry E.Vincenty,

Hills, Ohio [73] Assignee: Euclid, Inc., Cleveland, Ohio [22] Filed:Aug. 13, 1970 211 Appl. No.: 63,444

Willoughby [52] US. Cl. ..298/1 H [51 Int. Cl ..F02b 75/10 [58] Field ofSearch ..298/l H [56] References Cited UNITED STATES PATENTS 3,290,09312/1966 Eaton ..298/l H 2,721,097 10/1955 Rittenhouse ..298/l H FOREIGNPATENTS OR APPLICATIONS 798,255 1/ 1956 Great Britain ..298/l H PrimaryExaminer-Benjamin Hersh Assistant Examiner-Robert R. SongAttorney-Watts, Hoffmann, Fisher & l-leinke [57] ABSTRACT A load dumpingvehicle including a frame, a gas turbine engine supported by the frameand a dump body pivotally connected to the frame for movement relativeto the frame between a load carrying position and a dump position.Exhaust from the engine is ducted under the dump body through first andsecond exhaust ducts. Part of the exhaust flows into the dump body toheat the load. The ducts are connected at adjacent ends by a couplingstructure which seals the juncture of the exhaust ducts when the dumpbody is in its load carrying and in its dump positions.

15 Claims, 6 Drawing Figures PATENTEBnm 3 I972 SHEET 2 OF 2 Fig. 6

INVENTOR. HE/VEY E. VINCENT) flaw:

ATTORNEYS.

EXHAUST SYSTEM FOR A LOAD DUMPING VEHICLE BACKGROUND OF THE INVENTION 1.Field of the Invention The present invention relates to a load dumpingvehicle and more particularly relates to a load dumping vehicle havingan exhaust system constructed to continuously heat the dump bodyregardless of the positionof the dump body.

2. The Prior Art Load dumping vehicles, such as dump trucks, which arepowered by internal combustion engines have been constructed so thatwhen a dump body of the vehicle is operated between its load carryingand dump positions an exhaust system associated with an engine of thevehicle was articulated. In such arrangements, at, least a portion ofthe engine exhaust system moved as the dump body moved.

At one time a problem with dump vehicles was that the payload wouldfreeze in the dump body during cold weather conditions. To overcomethis, heated dump bodies were developed. These dump bodies were heatedby ducting exhaust gases from the vehicle engine through passages formedin the body. The exhaust gases heated the body sufficiently to preventthe load from freezing and adhering to the body.

In one type of prior construction, the exhaust gas entered the dump bodyvia a vertical stack which extended into an opening in the dump bodyadjacent the operators cab. When a load was dumped, the dump body raisedup and was disconnected from the exhaust stack. The exhaust gases werethen expelled from the stack into the atmosphere in the vicinity of thevehicle cab. Thus, the operator of the truck was frequently exposed tothe exhaust gases. Because those gases could be both irritating anddangerous, this type of construction for heating the dump bodies was notentirely desirable.

Vehicles have been constructed which overcame the problem of excessiveoperator exposure to the exhaust gases. One successful system employedan auxiliary exhaust pipe which extended rearwardly of the vehicle. Whenthe vehicle body was down, a valve shut off the auxiliary exhaust pipeand directed the exhaust gases into the body. When the body was up,i.e., in its dumping position, the main stack was shut off and gaseswere diverted through the auxiliary exhaust pipe.

Another proposal was to continuously heat the dump by means of apermanent connection between the dump body ducting and the engineexhaust system. In this proposal, the engine exhaust system included arotatable joint between one exhaust pipe connected to the engine andanother exhaust pipe connected to the dump body. This rotatable jointwas intended to be aligned and coaxial with the axis of rotation of thedump body on the vehicle frame. When the dump body was raised andlowered, the joint would swivel about its axis enabling a continuousflow of exhaust gas through the joint to the dump body.

Positioning a swivel joint in an exhaust system coaxially with the pivotaxis of a dump body was difficult, and maintaining the joint properlypositioned was even more difficult. Accordingly this proposal was nottotally satisfactory.

Another disadvantage of this continuously heated system was that theentire exhaust flow from the engine was directed into the dump body toheat the body at all times. Therefore when warm or dry loads were beingtransported, the dump body was heated even though heating was notnecessary. Furthermore, ducting exhaust gases into the dump body at alltimes caused constant relatively large back pressures on the vehicleengine which reduced its performance unnecessarily particularly whenmaximum heating of the dump body was not required.

SUMMARY OF THE INVENTION The present invention provides a new exhaustsystem for continuously heating the body of a load dumping vehicle andwhich is: simple in construction; usable as an exhaust system for anytype of internal combustion engine including a gas turbine engine;effective to seal against escape of exhaust gas between a fixed duct anda movable duct; and, not installed on the pivot axis of the dump body.

In a preferred embodiment of the invention, the load dumping vehicle isa dump truck powered by a gas turbine engine. The dump body is movableabout the axis of a pivot construction between a load carrying positionand a dump position. The exhaust of the vehicle and a second ductattached to the movable-dump body. The second duct moves with the dumpbody relative to the first duct.

The second duct includes one branch for directing the engine exhaustdirectly to atmosphere and another branch for directing the exhaustgases to atmosphere through passageways formed in the dump body. Thedump body is thus continuously heated by the engine exhaust regardlessof the position of the dump body relative to the vehicle frame.

A duct coupling structure is connected between adjacent ends of thefirst and second ducts in the vicinity of a pivot construction aboutwhich the dump body moves. This coupling includes a coupling memberdefining an exhaust flow passage which extends generally transverse tothe direction of the pivot axis.

The duct which is fixed to the frame extends freely into the couplingmember. The coupling member is connected to the dump body so that as thedump body rotates between its load carrying and dump positions, thecoupling member moves with the dump body relative to the fixed duct.

The coupling member cooperates with the fixed duct to provide a sealagainst the escape of exhaust gas from within the fixed duct when thedump body is in either of its noted positions. When the dump body is inits load carrying position, the fixed duct extends into the couplingmember on an angle with respect to the plane of the opening in thecoupling member. The angle between the duct and the opening in thecoupling member is such that the opening in the coupling member isforeshortened and thus closely surrounds the periphery of the duct.

The fixed duct supports a first peripheral sealing flange which isinclined with respect to the duct. The sealing flange engages a secondsealing flange disposed about the opening of the coupling member. Theseflanges are coplanar when the dump body is in the load carrying positionand are engaged to tightly seal about the fixed duct and the opening inthe coupling member.

When the dump body is in its dumping position, the coupling member ismoved to a location at which the fixed duct extends into the opening inthe coupling member at a second angle. This angle is such that the ductopening is foreshortened to closely surround the periphery of the end ofthe fixed duct. In this position, a third sealing flange on the ductengages the second sealing flange on the coupling member to seal againstthe escape of exhaust gas between the fixed duct and the couplingmember.

When the dump body is moving its load carrying and load dumpingpositions, the faces of the sealing flanges on the duct and couplingmember are disengaged. Some leakage of exhaust can thus occur. However,this leakage is minimal and does not occur over any appreciable periodof time since the dump body is not maintained in a position intermediatethe load carrying and dump positions. Furthermore, the coupling isremote from the operators cab so that even if exhaust leaks from thecoupling the operator is not exposed to it.

The exhaust ducts are preferably rectangular in cross sectional shapeand the coupling structure includes a tubular coupling member which isalso of generally rectangular cross sectional shape. The coupling memberhas a larger cross sectional area than the ducts. The rectangularopening in the coupling member is just slightly wider than the fixedduct but is of substantially greater height. This additional heightpermits the fixed duct to extend into the coupling opening at theaforementioned angles for sealing yet enables relative movement betweenthe duct and coupling member without interference.

The preferred coupling member is spaced from the pivot axis of the dumpbody. Hence, the coupling member orbits about the pivot axis when thedump body moves. Because of this construction, an exhaust systemconstructed according to the invention is installable on any dump truckwithout requiring any particular dump body or frame construction toaccommodate the coupling and associated ducts.

The new exhaust system also incorporates an exhaust deflecting vane forcontrolling the amount of exhaust gas which flows into the dump body toheat. This ena bles the degree of heating of the dump body to becontrolled without unduly increasing exhaust back pressures at theengine.

A principal object of the present invention is the provision of a newand improved exhaust system for continuously heating the body of a loaddumping vehicle in which exhaust ducts and their couplings arearticulated as the dump body is moved between its load carrying and itsdumping position and with the coupling being of simple construction yetsufficiently rugged to operate over long periods of use.

Other objects and advantages of the invention will become apparent fromthe following detailed description thereof made with reference to theaccompanying drawings which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side elevationalview of the load dumping vehicle embodying the present invention;

FIG. 2 is a view similar to FIG. 1 showing a dump body of the vehicle ina load dumping position;

FIG. 3 is a top plan view of the vehicle shown in FIG.

FIG. 4 is a fragmentary cross sectional view of a portion of the vehicleillustrated in FIG. 1;

FIG. 5 is a fragmentary cross sectional view of a portion of the vehicleillustrated in FIG. 2; and,

FIG. 6 is a cross sectional view as seen from the plane indicated by theline 6-6 of FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT A dumpable vehicle 10 in the formof an off-the-road dump truck is illustrated in FIGS. 1 and 2. The truck10 includes a frame 11 which is supported by ground engaging the drivingwheels 12. The frame 11 supports an operators cab 14, a dump body 15 anda gas turbine engine 16.

The dump body 15 is formed by a floor plate assembly 17, side linerplates 18 and a front plate 19. The floor plate assembly includes afloor plate 17a and structural support members 17b, 17c, 17d, l7e. Themembers l7b-l7d extend along part of the perimeter of the floor plateproper. The support members 17b, 17d extend along the junctures of thefloor plate 17a and the side plates 18 while the member extends alongthe juncture of the front plate 19 and the floor plate. The structuralmember l7e extends between the members 17b, 17d near the rearward end ofthe floor plate.

The members 17b-17e define a passageway 20 about the junctures of thefloor plate and with the side and front plates. This passageway conductsexhaust gas from the engine 16 to the atmosphere in the direction shownby the arrows in FIG. 3. The exhaust gas heats the dump body as it flowsthrough the structural members, and is subsequently directed into theatmosphere at the rear of the body via an opening at the rearward end ofthe support member 17d.

The dump body 15 is pivotally connected to the frame 11 for movementbetween a load carrying position, illustrated in FIG. 1, and a loaddumping position illustrated in FIG. 2. A pivot construction 21 connectsthe dump body to the frame and includes support arms 22 which extendfrom the dump body to trunions 24 which project from the frames. Thetrunions 24 support the arms 22 for rotation about a pivot axis 26extending transversely to the frame 1 1.

The gas turbine engine 16 provides a source of driving power for thetruck 10 via an electric generator, not shown, which is driven from theoutput shaft of the engine. The generator produces electrical power foroperating electric motors associated with each of the vehicle wheels.The generator may also provide the motive power for operating ahydraulic system which actuates various components on the vehicle. Thehydraulic system includes actuators 28 for moving the dump body betweenits load carrying and dumping positions. I

An exhaust system 30 directs exhaust from the engine 16 along the frame11. The exhaust system 30 expells the exhaust gas at the rear of thedump body and also directs a part of the exhaust into the passageway 20for heating the dump body.

The system 30 preferably extends along the longitudinal centerline ofthe truck and includes a first exhaust duct 31 which is fixed relativeto the frame 1 1, a second exhaust duct 33 fixed to the dump body 15,and a duct coupling structure 34 enabling the duct 33 to move relativeto the duct 31 as the dump body moves. The

coupling 34 seals the exhaust system against the escape of exhaust gaswhen the dump body is in its load carrying position and in its dumpingposition.

As is best seen in FIGS. 3-5, the ends 35, 37 of the ducts 31, 33,respectively, are located adjacent each other and spaced from the pivotaxis 26. The duct coupling structure 34 is located between the ends 35,37 of the ducts to insure against the escape of exhaust gas from thejuncture of the duct ends as well as to enable the ducts to moverelative to each other when the dump body is moved between itsaforementioned positrons.

The ducts 31, 33 are of rectangular cross sectional shape in thevicinity of their adjacent ends. The duct coupling structure 34 includesa tubular coupling body or member 40 having a generally rectangularcross sectional shape and which defines a rectangular opening 41 throughwhich the duct 31 extends. The coupling body 40 is defined by planarside walls 42, 44 and arcuately curved upper and lower walls 46, 48.Each of the walls 46, 48 has a center of curvature located substantiallyon the rotation axis 26 of the dump body. The duct 33 may be cylindricaladjacent the engine exhaust remote from the duct 31 depending on theconfiguration of the engine exhaust section.

The width of the opening 41, i.e., the distance between the side walls42, 44, is slightly larger than the width of the duct 31. The height ofthe opening, i.e., the distance between the walls 46, 48, issubstantially greater than the height of the duct 31.

In the illustrated embodiment, the coupling body or member 40 isintegral with the duct 33. Both the duct 33 and the coupling body 40 arerigidly connected to the dump body 15. As will be apparent from thefollowing, the coupling body 40 could be connected to the duct 31 andframe 11 if desired.

The duct 31 extends freely into the coupling body 40 at an angle withrespect to the plane of the opening 41; At this angle (FIG. 2) therectangular shape of the opening 41 is foreshortened so that it closelysurrounds the periphery of the duct 31. The duct 31 carries a peripheralsealing flange 50 which projects from the periphery of the duct. Theflange 50 extends continuously around the duct in a plane which isinclined with respect to the longitudinal axis or centerline of theduct. The flange 50 is of substantially the same size and shape as theboundary of the opening 41.

The sealing flange 50 engages a sealing flange 52 carried by thecoupling body 40 when the dump body is in the load carrying position(FIGS. 1 and 4). The flange 52 extend about the opening 41 and in theplane of the opening. The sealing flanges 50, 52 are coplanar and areengaged peripherally about the duct 31 and opening 41 when the dump bodyis in the load carrying position. Engagement of these flanges preventsthe escape of exhaust gases from between the coupling body 40 and theduct 31. Preferably the sealing flanges each carry a suitable gasketwhich defines a planar sealing face. These faces are engaged to assurean adequate seal between the engaged flanges.

When the dump body is moved toward its dumping position, the couplingbody 40 orbits about the axis 26 relative to the duct 31 disengaging thesealing flanges 50, 52. When the dump body is in the dumping position(FIGS. 2 and 5) the coupling body 40 has moved sufficiently that theduct 31 again extends into the opening 41 at an angle with respect tothe plane of the opening 41. This angle is such that the opening 41 isagain foreshortened to closely surround the periphery of the duct 31.

When the coupling body 40 and the duct 31 are positioned as described, asealing flange 54 carried at the end of the duct 31 engages the sealingflange 52. In the illustrated and preferred embodiment, the sealingflange 54 bounds the end opening of the duct 31. This opening and theflange are inclined with respect to the duct axis. The flange 54 iscoplanar with the opening 41 and flange 52 when the body is in itsdumping position. The flanges 54, 52 are of essentially the same sizeand shape. Thus when the body is in its dumping position, these flangesare tightly engaged to seal the juncture of the coupling member and theend of the duct 31.

The sealing flange 54 and the side of the sealing flange 52 whichengages the flange 54 are preferably provided with gaskets. The gasketsdefine planar sealing faces to insure a positive seal between thecoupling member and the duct.

The arcuate upper and lower walls 46, 48 of the coupling member assurethat the coupling member clears the end of the duct 31 as the couplingmember orbits between its sealing positions with respect to the duct.

The duct coupling structure 34 does not seal the juncture between theducts 31, 33 when the dump body is moving between its load carryingposition and its dumping position; however, the curved wall constructionof the coupling body guides the exhaust into the duct 33 from the duct31. Leakage, if any, during this transitional period of operation of thedump body 15 is minimal and remote from the operators cab 14.

The duct 33 has two duct branches 56, 58. The duct branch 56 extendsrearwardly from the coupling 34 and is open to atmosphere at the rear ofthe dump body. The duct branch 58 extends upwardly from the duct branch56 and is attached to the structural member 17s with the duct branch 58opening into the passageway 20. A partition 60 blocks the passageway 20between the structural member 17d and the duct branch 58 so that exhaustgas in the passageway 20 is required to flow through the structuralmembers 17b-l7c as shown by the arrows in FIG. 3.

The volume of exhaust gas flowing into the passageway 20 to heat thedump body 15 is adjustable to control the degree of heating of the dumpbody. Preferably a vane 62 is supported in the duct 33 between thebranches 56, 58. The vane 62 is connected to a position adjusting rod 64which is rotated to adjust the position of the vane in the duct 33. Therod 64 is rotatably supported by the side walls of the duct 33 and maybe manually rotated to adjust the vane position.

As is seen in FIG. 4 if the rod 64 is rotated clockwise, the vane 62reaches a limit of its travel in which the flow of engine exhaustpassing from the system 30 through the duct branch 56 is maximum. Whenthe rod 64 is rotated counterclockwise, the vane moves to a limitposition at which the engine exhaust flow through the passageway 20 ismaximum, producing maximum heating of the dump body.

A suitable locking device (not shown) may be employed to fix the rod 64and vane 62 in an adjusted position. This device can consist of aconventional friction clutch, or removable blocking pins, etc.

When the truck is used in a warm climate, the vane can be locked in theposition providing minimum heating of the dump body. This minimizes theengine exhaust back pressure so that engine performance is optimized.

The vane is adjustable to a number of positions between its limitpositions so that the dump body heating exhaust flow can be controlledaccording to climatic conditions. This adjustability enables the engineto operate with minimum exhaust back pressure for any given heatingrequirement of the dump body.

While only a single embodiment of the invention has been illustrated anddescribed in detail, the invention is not to be considered limited tothe precise construction shown. It is intended to cover hereby alladaptations, modifications and uses of the disclosed structure whichcome within the scope of the invention.

What is claimed is:

1. In a vehicle having an engine supported on a frame, a body pivotallymovable with respect to said frame about a pivot axis and means forpivoting said body about said axis between first and second positions;an exhaust system for directing exhaust gas from said engine into heattransfer relationship with said body for heating the same comprising:

a. a first exhaust duct carried by said frame;

b. a second exhaust duct;

c. ends of said ducts disposed near each other;

d. duct coupling structure between said ends of said ducts for directingexhaust in a direction generally transverse to the direction of extentof said pivot axis; and,

. said duct coupling structure including:

1 a coupling member defining an opening;

2. one of said ducts extending into said coupling member through saidopening;

3. said opening in said member having a larger cross sectional area thanthe cross sectional area of said one duct; said means for pivoting saidbody effecting relative movement between said one duct and said couplingmember as said body pivots between said posit-ions; and,

. said one duct extending into said opening in said coupling member atfirst and second angles when said body is in said first and secondpositions, respectively, with said opening in said coupling memberextending closely about said one duct to form a seal.

2. A vehicle as claimed in claim 1 wherein said coupling member is fixedto said body for pivotal movement therewith.

3. A vehicle as claimed in claim 2 wherein said coupling member isspaced from said pivot axis and orbits about said axis when said bodymoves between said first and second positions.

4. A vehicle as claimed in claim 1 wherein said one duct has a polygonalcross sectional shape and said opening has a polygonal shape similar tothe shape of said one duct, said opening having substantially the samedimension as said duct measured parallel to said pivot axis and a largerdimension than said duct measured radially from said pivot axis.

5. A vehicle as claimed in claim 1 and further including first andsecond sealing flanges connected to said one duct at spaced locations, athird sealing flange connected to said coupling member and disposedabout said opening, said third flange engaging said first flange whensaid body is in one of said positions to seal the juncture of saidcoupling member and said one duct, said third flange engaging saidsecond flange when said body is in its other position for sealing saidjuncture.

6. A vehicle as claimed in claim 5 wherein said first and second flangesdefine planar sealing faces engageable with said third flange, saidsealing faces extending about said one duct in a plane which is inclinedrelative to the longitudinal axis of said one duct.

7. A vehicle as claimed in claim 6 wherein said third flange definesfirst and second planar sealing faces engageable with the sealing faceson said first and second flanges respectively.

8. A vehicle as claimed in claim 1 and further including an exhaustpassageway in said body, said second duct communicating exhaust gas tosaid passageway, and a movable flow controlling member in said secondduct, said movable member controlling the amount exhaust gas flowing tosaid passageway.

9. A vehicle as claimed in claim 8 wherein said movable member comprisesa vane having a first limit position in which the flow of exhaust gas tosaid passageway is minimum and a second limit position in which the flowof exhaust gas in said passageway is maximum, and structure forpositioning said vane between said first and second positions.

10. In a load dumping vehicle:

a. a frame;

b. a gas turbine engine supported by said frame;

c. a dump body connected to said frame by a pivot construction andmovable about a pivot axis of said pivot construction between a firstload carrying position and a second load dumping position;

d. a first exhaust duct fixed with respect to said frame andcommunicating with said engine;

e. a second exhaust duct fixed to said dump body for directing engineexhaust gas into heat exchange relationship with part of said body;

f. ends of said ducts opening adjacent each other for enabling exhaustto flow from said first duct to said second duct;

g. duct coupling structure between said first and second exhaust ducts,said coupling structure comprising:

1. a tubular coupling member having a first opening into which saidfirst duct extends and a second opening communicating with said secondduct, said coupling member directing exhaust gas from said first duct tosaid second duct in a direction generally transverse to said pivot axis;

2. means supporting said coupling member for movement with said dumpbody relative to said first duct orbitally about said pivot axis; and,

3. at least a part of said coupling member sealingly engaging said firstduct when said dump body is in said first position and when said dumpbody is in said second position.

11. In a vehicle as claimed in claim 10 and further including first andsecond sealing flanges extending peripherally about said first duct atspaced locations, said flanges having an inner peripheral boundaryadjacent said first duct and an outer peripheral boundary and includingsealing faces disposed in planes intersecting said pivot axis andinclined with respect to said first duct, said first opening in saidcoupling member having substantially the same size and shape as saidinner peripheral boundaries of said first and second flanges and withone of said sealing faces engaging said coupling member adjacent saidopening when said dump body is in said first position and the othersealing face engaging said coupling member adjacent said opening whensaid dump body is in said second posi tion.

12. A vehicle as claimed in claim 11 wherein the transverse crosssectional shape of said first duct and the shape of said opening in saidcoupling member are polygonal and have the same number of sides anddifferent areas.

13. In a vehicle as claimed in claim wherein said second duct includes afirst branch for directing engine exhaust gas to atmosphere, a secondbranch for directing engine exhaust gas into heat exchange relationshipwith at least part of said dump body, and means for controlling theproportion of engine exhaust gas directed through said second branch.

14. In a load dumping vehicle having an engine, a frame, and a dump bodypivotally supported on said frame, an exhaust system comprising:

a. a first exhaust duct supported by said frame;

b. a second exhaust duct attached to said body and movable therewith assaid dump body pivots relative to said frame;

c. means for coupling said first duct to said second duct forcontinuously directing engine exhaust through said ducts;

d. said second duct including a first duct branch for directing exhaustgas into the atmosphere and a second duct branch for directing exhaustgas into heat transfer relationship with portions of said dump body;and,

e. flow control means for governing the proportion of exhaust gasflowing through said duct branches, said flow control means comprising avane member supported in said first duct branch downstream from thejuncture of said duct branches for movement between adjusted positionsto vary the flow of exhaust gas in said first and second branches and asupport member connecting said vane member to said first duct branch foradjusting movement in said duct branch.

15. In a wheeled vehicle including a frame, a prime mover of a typewhich emits exhaust gases at an elevated temperature carried by theframe and a body tiltably mounted on the frame for movement from aload-carrying to a dump position and return, an improved exhaust systemcomprising:

a. a first exhaust duct connected to the prime mover and to the frame;

b. a second exhaust duct connected to the body;

c. duct coupling structure in telescopic relationship with one of theducts and connecting the ducts in exhaust transmitting communication;

d. the telescopic relationship of said coupling structure and the oneduct beinghrelatively changeable from a first position when e body is inits loadcarrying position to a second position when the body is in itsdump position such that the amount of telescopic relationship is greaterin one position than the other and the ducts are maintained in exhaustconducting communication by the coupling structure in both positions;and,

e. duct means connecting a selected duct to exhaust passages within thebody for heating the body.

1. In a vehicle having an engine supported on a frame, a body pivotallymovable with respect to said frame about a pivot axis and means forpivoting said body about said axis between first and second positions;an exhaust system for directing exhaust gas from said engine into heattransfer relationship with said body for heating the same comprising: a.a first exhaust duct carried by said frame; b. a second exhaust duct; c.ends of said ducts disposed near each other; d. duct coupling structurebetween said ends of said ducts for directing exhaust in a directiongenerally transverse to the direction of extent of said pivot axis; and,e. said duct coupling structure including:
 1. a coupling member definingan opening;
 2. one of said ducts extending into said coupling memberthrough said opening;
 3. said opening in said member having a largercross sectional area than the cross sectional area of said one duct; 4.said means for pivoting said body effecting relative movement betweensaid one duct and said coupling member as said body pivots between saidpositions; and,
 5. said one duct extending into said opening in saidcoupling member at first and second angles when said body is in saidfirst and second positions, respectively, with said opening in saidcoupling member extending closely about said one duct to form a seal. 2.one of said ducts extending into said coupling member through saidopening;
 2. means supporting said coupling member for movement with saiddump body relative to said first duct orbitally about said pivot axis;and,
 2. A vehicle as claimed in claim 1 wherein said coupling member isfixed to said body for pivotal movement therewith.
 3. A vehicle asclaimed in claim 2 wherein said coupling member is spaced from saidpivot axis and orbits about said axis when said body moves between saidfirst and second positions.
 3. at least a part of said coupling membersealingly engaging said first duct when said dump body is in said firstposition and when said dump body is in said second position.
 3. saidopening in said member having a larger cross sectional area than thecross sectional area of said one duct;
 4. said means for pivoting saidbody effecting relative movement between said one duct and said couplingmember as said body pivots between said positions; and,
 4. A vehicle asclaimed in claim 1 wherein said one duct has a polygonal cross sectionalshape and said opening has a polygonal shape similar to the shape ofsaid one duct, said opening having substantially the same dimension assaid duct measured parallel to said pivot axis and a larger dimensionthan said duct measured radially from said pivot axis.
 5. A vehicle asclaimed in claim 1 and further including first and second sealingflanges connected to said one duct at spaced locations, a third sealingflange connected to said coupling member and disposed about saidopening, said third flange Engaging said first flange when said body isin one of said positions to seal the juncture of said coupling memberand said one duct, said third flange engaging said second flange whensaid body is in its other position for sealing said juncture.
 5. saidone duct extending into said opening in said coupling member at firstand second angles when said body is in said first and second positions,respectively, with said opening in said coupling member extendingclosely about said one duct to form a seal.
 6. A vehicle as claimed inclaim 5 wherein said first and second flanges define planar sealingfaces engageable with said third flange, said sealing faces extendingabout said one duct in a plane which is inclined relative to thelongitudinal axis of said one duct.
 7. A vehicle as claimed in claim 6wherein said third flange defines first and second planar sealing facesengageable with the sealing faces on said first and second flangesrespectively.
 8. A vehicle as claimed in claim 1 and further includingan exhaust passageway in said body, said second duct communicatingexhaust gas to said passageway, and a movable flow controlling member insaid second duct, said movable member controlling the amount exhaust gasflowing to said passageway.
 9. A vehicle as claimed in claim 8 whereinsaid movable member comprises a vane having a first limit position inwhich the flow of exhaust gas to said passageway is minimum and a secondlimit position in which the flow of exhaust gas in said passageway ismaximum, and structure for positioning said vane between said first andsecond positions.
 10. In a load dumping vehicle: a. a frame; b. a gasturbine engine supported by said frame; c. a dump body connected to saidframe by a pivot construction and movable about a pivot axis of saidpivot construction between a first load carrying position and a secondload dumping position; d. a first exhaust duct fixed with respect tosaid frame and communicating with said engine; e. a second exhaust ductfixed to said dump body for directing engine exhaust gas into heatexchange relationship with part of said body; f. ends of said ductsopening adjacent each other for enabling exhaust to flow from said firstduct to said second duct; g. duct coupling structure between said firstand second exhaust ducts, said coupling structure comprising:
 11. In avehicle as claimed in claim 10 and further including first and secondsealing flanges extending peripherally about said first duct at spacedlocations, said flanges having an inner peripheral boundary adjacentsaid first duct and an outer peripheral boundary and including sealingfaces disposed in planes intersecting said pivot axis and inclined withrespect to said first duct, said first opening in said coupling memberhaving substantially the same size and shape as said inner peripheralboundaries of said first and second flanges and with one of said sealingfaces engaging said coupling member adjacent said opening when said dumpbody is in said first position and the other sealing face engaging saidcoupling member adjacent said opening when said dump body is in saidsecond position.
 12. A vehicle as claimed in claim 11 wherein thetransverse cross sectional shape of said first duct and the shape ofsaid opening in said coupling member are polygonal and have the samenumber of sides and different areas.
 13. In a vehicle as claimed inclaim 10 wherein said second duct includes a first branch for directingengine exhaust gas to atmosphere, a second branch for directing engineexhaust gas into heat exchange relationship with at least Part of saiddump body, and means for controlling the proportion of engine exhaustgas directed through said second branch.
 14. In a load dumping vehiclehaving an engine, a frame, and a dump body pivotally supported on saidframe, an exhaust system comprising: a. a first exhaust duct supportedby said frame; b. a second exhaust duct attached to said body andmovable therewith as said dump body pivots relative to said frame; c.means for coupling said first duct to said second duct for continuouslydirecting engine exhaust through said ducts; d. said second ductincluding a first duct branch for directing exhaust gas into theatmosphere and a second duct branch for directing exhaust gas into heattransfer relationship with portions of said dump body; and, e. flowcontrol means for governing the proportion of exhaust gas flowingthrough said duct branches, said flow control means comprising a vanemember supported in said first duct branch downstream from the junctureof said duct branches for movement between adjusted positions to varythe flow of exhaust gas in said first and second branches and a supportmember connecting said vane member to said first duct branch foradjusting movement in said duct branch.
 15. In a wheeled vehicleincluding a frame, a prime mover of a type which emits exhaust gases atan elevated temperature carried by the frame and a body tiltably mountedon the frame for movement from a load-carrying to a dump position andreturn, an improved exhaust system comprising: a. a first exhaust ductconnected to the prime mover and to the frame; b. a second exhaust ductconnected to the body; c. duct coupling structure in telescopicrelationship with one of the ducts and connecting the ducts in exhausttransmitting communication; d. the telescopic relationship of saidcoupling structure and the one duct being relatively changeable from afirst position when the body is in its load-carrying position to asecond position when the body is in its dump position such that theamount of telescopic relationship is greater in one position than theother and the ducts are maintained in exhaust conducting communicationby the coupling structure in both positions; and, e. duct meansconnecting a selected duct to exhaust passages within the body forheating the body.